Automobiles have been the major mode of transportation for many decades. From early steam powered engines to the predecessors of modern day internal combustion engines, the energy released through combustion reactions has propelled the automobile, both literally and figuratively, across miles of highways and through years of calibrations, modifications, and improvements. Since the early days of automobiles there have been many great and important developments in engine performance, power, and efficiency. The latter of these listed developments, increasing engine efficiency, is perhaps the most important challenge facing car-makers today because of the limited amount of available combustible materials (i.e. hydrocarbon fuels). Therefore, car-makers have been continuously striving to increase engine efficiency by decreasing hydrocarbon fuel consumption.
Car-makers have generally approached this challenge in one of three ways: (1) developing internal combustion engines with higher gas mileage ratings, (2) developing electric cars to remove the automobile's dependence on hydrocarbon fuels to a remote location (i.e. coal power plant), and (3) developing hybrid automobiles that take advantage of both combustion propelled and electrically driven motors. While each of these approaches has advantages and disadvantages when compared to the others, the common underlying challenge in all three of these approaches is making an efficient automobile that can still provide enough power to match the power demanded, both in quantity and quality, during high-power driving situations (e.g. accelerating, climbing a hill, towing).
Automobiles with “high” gas mileage engines are very effective at operating efficiently by using relatively low quantities of fuel. However, not only are these “high” gas mileage engines still relatively inefficient at consuming hydrocarbon fuels (maybe up to 40 miles/gallon), these engines are also generally smaller and less powerful and are not well-suited for providing sufficient power to meet the constantly varying demands that are placed on a conventional automobile engine. For example, when a driver presses the accelerator pedal, the driver expects (demands) the engine to accelerate the vehicle to a faster speed, drive the vehicle up a hill, tow a load, carry a load, or otherwise propel the vehicle with substantial force. Conventional high gas mileage engines generally struggle to meet these demands and, if they are able to meet them, sacrifice efficiency to do so. These engines are not able to efficiently match the power supply with the power demand.
Conventional electric vehicles often include a bank of rechargeable batteries that propel the vehicle. While electric vehicles may be effective at supplying the motor with enough electricity to propel the vehicle through various power demand situations, the limited driving range and the long recharge time of the batteries are substantial drawbacks that limit the legitimacy of the electric vehicle as a practical solution to the current problem.
Hybrid vehicles use both internal combustion engines and electric batteries in various configurations to propel a vehicle. For example conventional hybrid vehicles may employ a configuration where the internal combustion engine supplements the electric propulsion during high-power driving situations. In another configuration, the internal combustion engine may recharge the batteries so that the batteries can meet the varying demands encountered during driving. However, the issue still remains that, regardless of whether the electric motor manages the high demand situations while the internal combustion engine manages the low demand situations or vice-versa, the engine will still need to have the capacity to generate the power needed (either horsepower or electric power) to handle the high demand situations.